Effect of some dopants on temperature of high-temperature phase transitions of Na0.5Bi0.5TiO3-0.06BaTiO3 lead-free relaxor ferroelectrics ceramics seen via acoustic emission

Na0.5Bi0.5TiO3-0.06BaTiO(3) relaxor ferroelectrics ceramic samples doped with 1 wt% of CuO, Fe2O3, Sb2O3, La2O3 and Ta2O5 were investigated by means of dielectric and acoustic emission methods in the high-temperature range. Dielectric constants exhibited a wide and smeared maximum at the temperature T-m, accompanied by acoustic emission sharp bursts, but the dielectric constants exhibited no anomaly when further transiting into cubic paraelectric phase at the temperature T-p, accompanied by acoustic emission sharp bursts, too. Based on acoustic emission data the shifts of these two temperatures, T-m and T-p, in dependence on a wt% of the incorporated ions as well as the acoustic emission count rate distribution in dependence on the incorporated ions radii were plotted and discussed.